1. Field of the Invention
This invention relates to agricultural harvesting equipment in general, and more precisely to lubricating the shaker heads of nut and fruit tree-shaker type harvesting equipment.
2. Description of the Prior Art
Over the years the agricultural industry has developed equipment which quickly harvests the fruit of entire trees in a matter of seconds. One type of fruit and nut tree harvester now widely used has two extending mechanical shaker arms which project outward from the side or front of the harvester. The shaker arms are designed to temporarily clamp against the base of the tree. The shaker arms are then vibrated to shake the fruit or nuts out of the tree. This disclosure is directed at this type of harvesting equipment.
To protect the trees from damage, pliable rubbery padding is attached to the distal ends of the shaker arms. The shaker heads, as they commonly referred to in the industry, each include the distal end of each shaker arm and the pliable padding attached thereon. The padding of a shaker head normally includes a main shaker pad, a sling, and a slip pad. The shaker pad is usually a large cylindrical structure supported on the distal end of the shaker arm by the rectangular, somewhat thin flexible pad referred to as the sling. A second rectangular flexible pad, commonly known as the slip pad, is attached to the upper surface of the shaker arm and draped downward over the exterior of the sling. The lower or bottom side of the slip pad is releasably attached to the bottom surface of the shaker arm by elastic cords and hooks. The elastic cord attachment method of the slip pad allows the bottom of the pad to be unhooked and flipped upward onto the top of the shaker arm to expose the outer surface of the sling. Exposing the sling allows a heat resistant lubricant or grease to be manually applied with a brush between the sling and the slip pad to decrease the friction between the two pads during shaking. The lubricant allows the slip pad to remain substantially stationary against the tree while the majority of the friction created by the vibration of the shaker head is between the sling and the slip pad and not the bark of the tree.
Unfortunately, even with the lubricating grease, friction is still present between the layers of padding during vibration, and consequently heat is developed in the pads. Due to the high temperatures developed by the rapid movement of the sling against the slip pad, the normally thick lubricant becomes thin, and is forced out from between the padding dropping to the ground. The lubricant must be manually reapplied periodically, usually every thirty to sixty minute of continuous tree shaking. If the lubricant is not applied often enough, the heat in the shaker head will continue to rise and concentrate. This concentrated heat causes the materials of the padding to deteriorate rapidly, shortening the life of the expensive pads.
When the harvest of an orchard has been contracted by the tree, or when under adverse weather conditions, time is of the essence in harvesting. Applying lubricant using conventional methods will usually take one man five to ten minutes. The time required to periodically apply lubricant can reduce overall profits since the machine is shut down during the lubricating operation. The tendency to stretch the time between lubrications will and does occur much to the detriment of the padding.